bernard borredon / PCF8574

Complete PCF8574 and PCF74A library with interrupt handling

Dependents:   Nucleo_PCF8574_led_iic Dawson_Controller

PCF8574.h@0:6d75da25c179, 2012-07-14 (annotated)

Committer:
bborredon
Date:
Sat Jul 14 08:20:07 2012 +0000
Revision:
0:6d75da25c179
[mbed] converted /I2c/PCF8574

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bborredon 0:6d75da25c179 1 #ifndef PCF8574__H_
bborredon 0:6d75da25c179 2 #define PCF8574__H_
bborredon 0:6d75da25c179 3
bborredon 0:6d75da25c179 4 // Includes
bborredon 0:6d75da25c179 5 #include <string>
bborredon 0:6d75da25c179 6 #include <bitset>
bborredon 0:6d75da25c179 7
bborredon 0:6d75da25c179 8 #include "mbed.h"
bborredon 0:6d75da25c179 9
bborredon 0:6d75da25c179 10 // Example
bborredon 0:6d75da25c179 11 /*
bborredon 0:6d75da25c179 12 #include <string>
bborredon 0:6d75da25c179 13
bborredon 0:6d75da25c179 14 #include "mbed.h"
bborredon 0:6d75da25c179 15 #include "PCF8574.h"
bborredon 0:6d75da25c179 16
bborredon 0:6d75da25c179 17 #define PCF8574_ADDR 0 // I2c PCF8574 address is 0x00
bborredon 0:6d75da25c179 18
bborredon 0:6d75da25c179 19 static void myerror(std::string msg)
bborredon 0:6d75da25c179 20 {
bborredon 0:6d75da25c179 21 printf("Error %s\n",msg.c_str());
bborredon 0:6d75da25c179 22 exit(1);
bborredon 0:6d75da25c179 23 }
bborredon 0:6d75da25c179 24
bborredon 0:6d75da25c179 25 void pcf8574_it(uint8_t data, PCF8574 *o)
bborredon 0:6d75da25c179 26 {
bborredon 0:6d75da25c179 27 printf("PCF8574 interrupt data = %02x\n",data);
bborredon 0:6d75da25c179 28 }
bborredon 0:6d75da25c179 29
bborredon 0:6d75da25c179 30 DigitalOut led2(LED2);
bborredon 0:6d75da25c179 31
bborredon 0:6d75da25c179 32 int main()
bborredon 0:6d75da25c179 33 {
bborredon 0:6d75da25c179 34 PCF8574 pcf(p9,p10,PCF8574_ADDR,true); // Declare PCF8574A i2c with sda = p9 and scl = p10
bborredon 0:6d75da25c179 35 uint8_t data;
bborredon 0:6d75da25c179 36
bborredon 0:6d75da25c179 37 led2 = 0;
bborredon 0:6d75da25c179 38
bborredon 0:6d75da25c179 39 // Set all IO port bits to 1 to enable inputs and test error
bborredon 0:6d75da25c179 40 data = 0xFF;
bborredon 0:6d75da25c179 41 pcf = data;
bborredon 0:6d75da25c179 42 if(pcf.getError() != 0)
bborredon 0:6d75da25c179 43 myerror(pcf.getErrorMessage());
bborredon 0:6d75da25c179 44
bborredon 0:6d75da25c179 45 // Assign interrupt function to pin 17
bborredon 0:6d75da25c179 46 pcf.interrupt(p17,&pcf8574_it);
bborredon 0:6d75da25c179 47
bborredon 0:6d75da25c179 48 if(pcf.getError() != 0)
bborredon 0:6d75da25c179 49 myerror(pcf.getErrorMessage());
bborredon 0:6d75da25c179 50
bborredon 0:6d75da25c179 51 // Get IO port (switch is used to flip bit 1)
bborredon 0:6d75da25c179 52 while(1) {
bborredon 0:6d75da25c179 53 wait(2.0);
bborredon 0:6d75da25c179 54 data = pcf;
bborredon 0:6d75da25c179 55 if(pcf.getError() != 0)
bborredon 0:6d75da25c179 56 myerror(pcf.getErrorMessage());
bborredon 0:6d75da25c179 57 led2 = !led2;
bborredon 0:6d75da25c179 58 }
bborredon 0:6d75da25c179 59
bborredon 0:6d75da25c179 60 return(0);
bborredon 0:6d75da25c179 61 }
bborredon 0:6d75da25c179 62 */
bborredon 0:6d75da25c179 63
bborredon 0:6d75da25c179 64 // Defines
bborredon 0:6d75da25c179 65 #define PCF8574_NoError 0x00
bborredon 0:6d75da25c179 66 #define PCF8574_BadAddress 0x01
bborredon 0:6d75da25c179 67 #define PCF8574_I2cError 0x02
bborredon 0:6d75da25c179 68 #define PCF8574_IntrError 0x03
bborredon 0:6d75da25c179 69
bborredon 0:6d75da25c179 70 #define PCF8574_MaxError 4
bborredon 0:6d75da25c179 71
bborredon 0:6d75da25c179 72 #ifndef BIT_SET
bborredon 0:6d75da25c179 73 #define BIT_SET(x,n) (x=x | (0x01<<n))
bborredon 0:6d75da25c179 74 #endif
bborredon 0:6d75da25c179 75 #ifndef BIT_TEST
bborredon 0:6d75da25c179 76 #define BIT_TEST(x,n) (x & (0x01<<n))
bborredon 0:6d75da25c179 77 #endif
bborredon 0:6d75da25c179 78 #ifndef BIT_CLEAR
bborredon 0:6d75da25c179 79 #define BIT_CLEAR(x,n) (x=x & ~(0x01<<n))
bborredon 0:6d75da25c179 80 #endif
bborredon 0:6d75da25c179 81 #ifndef BIT_GET
bborredon 0:6d75da25c179 82 #define BIT_GET(x,n) ((x >>n) & 0x1)
bborredon 0:6d75da25c179 83 #endif
bborredon 0:6d75da25c179 84
bborredon 0:6d75da25c179 85 static std::string _ErrorMessagePCF8574[PCF8574_MaxError] = {
bborredon 0:6d75da25c179 86 "",
bborredon 0:6d75da25c179 87 "Bad chip address",
bborredon 0:6d75da25c179 88 "I2C error (nack)",
bborredon 0:6d75da25c179 89 "Unable to create InterruptIn instance"
bborredon 0:6d75da25c179 90 };
bborredon 0:6d75da25c179 91
bborredon 0:6d75da25c179 92 // Class
bborredon 0:6d75da25c179 93 class PCF8574 {
bborredon 0:6d75da25c179 94 public:
bborredon 0:6d75da25c179 95 /*
bborredon 0:6d75da25c179 96 * Constructor, initialize the PCF8574 on i2c interface.
bborredon 0:6d75da25c179 97 * @param sda : sda i2c pin (PinName)
bborredon 0:6d75da25c179 98 * @param scl : scl i2c pin (PinName)
bborredon 0:6d75da25c179 99 * @param address : PCF8574 address between 0 and 7 (uint8_t)
bborredon 0:6d75da25c179 100 * @param typeA : PCF8574A if true, default false (bool)
bborredon 0:6d75da25c179 101 * @return none
bborredon 0:6d75da25c179 102 */
bborredon 0:6d75da25c179 103 PCF8574(PinName sda, PinName scl, uint8_t address, bool typeA = false);
bborredon 0:6d75da25c179 104
bborredon 0:6d75da25c179 105 /*
bborredon 0:6d75da25c179 106 * Read the IO pins level
bborredon 0:6d75da25c179 107 * @param : none
bborredon 0:6d75da25c179 108 * @return port value (uint8_t)
bborredon 0:6d75da25c179 109 */
bborredon 0:6d75da25c179 110 uint8_t read(void);
bborredon 0:6d75da25c179 111
bborredon 0:6d75da25c179 112 /*
bborredon 0:6d75da25c179 113 * Write to the IO pins
bborredon 0:6d75da25c179 114 * @param data : The 8 bits to write to the IO port (uint8_t)
bborredon 0:6d75da25c179 115 * @return none
bborredon 0:6d75da25c179 116 */
bborredon 0:6d75da25c179 117 void write(uint8_t data);
bborredon 0:6d75da25c179 118
bborredon 0:6d75da25c179 119 /*
bborredon 0:6d75da25c179 120 * Write to individual IO pin
bborredon 0:6d75da25c179 121 * @param pin : The pin number between 0 and 7 (uint8_t)
bborredon 0:6d75da25c179 122 * @param value : The pin value (uint8_t)
bborredon 0:6d75da25c179 123 * @return none
bborredon 0:6d75da25c179 124 */
bborredon 0:6d75da25c179 125 void write(uint8_t pin, uint8_t value);
bborredon 0:6d75da25c179 126
bborredon 0:6d75da25c179 127 /*
bborredon 0:6d75da25c179 128 * Write to IO pins with a bitset and a bitset mask (only bits set in mask are written)
bborredon 0:6d75da25c179 129 * @param data : The biset to write to the IO port (bitset<8>)
bborredon 0:6d75da25c179 130 * @param mask : The biset to write mask (bitset<8>)
bborredon 0:6d75da25c179 131 * @return none
bborredon 0:6d75da25c179 132 */
bborredon 0:6d75da25c179 133 void write(bitset<8> data, bitset<8> mask);
bborredon 0:6d75da25c179 134
bborredon 0:6d75da25c179 135 /*
bborredon 0:6d75da25c179 136 * Interrupt IO callback called when PCF8574 IO pins changed (falling edge)
bborredon 0:6d75da25c179 137 * @param intr : pin name connected to PCF8574 int pin (PinName)
bborredon 0:6d75da25c179 138 * @param ftpr : user callback function (void ftpr(unit8_t data, PCF8574 *o)).
bborredon 0:6d75da25c179 139 * data : PCF8574 IO port value
bborredon 0:6d75da25c179 140 * o : object instance address
bborredon 0:6d75da25c179 141 * @return none
bborredon 0:6d75da25c179 142 */
bborredon 0:6d75da25c179 143 void interrupt(PinName intr,void (*ftpr)(uint8_t data, PCF8574 *o));
bborredon 0:6d75da25c179 144
bborredon 0:6d75da25c179 145 /*
bborredon 0:6d75da25c179 146 * Get current error message
bborredon 0:6d75da25c179 147 * @param : none
bborredon 0:6d75da25c179 148 * @return current error message(std::string)
bborredon 0:6d75da25c179 149 */
bborredon 0:6d75da25c179 150 std::string getErrorMessage(void)
bborredon 0:6d75da25c179 151 {
bborredon 0:6d75da25c179 152 if(_errnum < PCF8574_MaxError)
bborredon 0:6d75da25c179 153 return(_ErrorMessagePCF8574[_errnum]);
bborredon 0:6d75da25c179 154 else
bborredon 0:6d75da25c179 155 return("errnum out of range");
bborredon 0:6d75da25c179 156 }
bborredon 0:6d75da25c179 157
bborredon 0:6d75da25c179 158 /*
bborredon 0:6d75da25c179 159 * Get the current error number (PCF8574_NoError if no error)
bborredon 0:6d75da25c179 160 * @param : none
bborredon 0:6d75da25c179 161 * @return current error number (uint8_t)
bborredon 0:6d75da25c179 162 */
bborredon 0:6d75da25c179 163 uint8_t getError(void);
bborredon 0:6d75da25c179 164
bborredon 0:6d75da25c179 165 /*
bborredon 0:6d75da25c179 166 * Memorize data IO port value and bits that have changed when interrupt
bborredon 0:6d75da25c179 167 * @param data : data IO port value when interrupt (bitset<8>)
bborredon 0:6d75da25c179 168 * @param changed : bits that have changed (bitset<8>)
bborredon 0:6d75da25c179 169 * @return none
bborredon 0:6d75da25c179 170 */
bborredon 0:6d75da25c179 171 void setIntrData(bitset<8> data, bitset<8> changed);
bborredon 0:6d75da25c179 172
bborredon 0:6d75da25c179 173 /*
bborredon 0:6d75da25c179 174 * Get data IO port value when and bits that have changed when interrupt
bborredon 0:6d75da25c179 175 * @param data : data IO port value when interrupt (bitset<8>&)
bborredon 0:6d75da25c179 176 * @param changed : bits that have changed (bitset<8>&)
bborredon 0:6d75da25c179 177 * @return none
bborredon 0:6d75da25c179 178 */
bborredon 0:6d75da25c179 179 void getIntrData(bitset<8>& data, bitset<8>& changed);
bborredon 0:6d75da25c179 180
bborredon 0:6d75da25c179 181 /*
bborredon 0:6d75da25c179 182 *Operator () (read)
bborredon 0:6d75da25c179 183 */
bborredon 0:6d75da25c179 184 operator uint8_t();
bborredon 0:6d75da25c179 185
bborredon 0:6d75da25c179 186 /*
bborredon 0:6d75da25c179 187 *Operator = (write)
bborredon 0:6d75da25c179 188 */
bborredon 0:6d75da25c179 189 PCF8574 &operator=(uint8_t data);
bborredon 0:6d75da25c179 190
bborredon 0:6d75da25c179 191 private:
bborredon 0:6d75da25c179 192 I2C _i2c; // Local i2c communication interface instance
bborredon 0:6d75da25c179 193 int _address; // Local pcf8574 i2c address
bborredon 0:6d75da25c179 194 int _PCF8574_address; // PCF8574 address
bborredon 0:6d75da25c179 195 uint8_t _errnum; // Error number
bborredon 0:6d75da25c179 196 bitset<8> _intr_data; // IO port value when interrupt
bborredon 0:6d75da25c179 197 bitset<8> _intr_bits_changed; // Bits that have changed on interrupt
bborredon 0:6d75da25c179 198 InterruptIn *_intr; // Internal InterruptIn object address
bborredon 0:6d75da25c179 199 uint8_t _intr_flag; // interrupt function has been called
bborredon 0:6d75da25c179 200 };
bborredon 0:6d75da25c179 201
bborredon 0:6d75da25c179 202 #endif